This Valentine's Day, you may want to consider taking your significant other on a trip rather than buying flowers.

A new survey out today by the U.S. Travel Association has found that couples who travel together have better relationships -- and better sex -- than those who don't.

Nearly two-thirds of couples surveyed say a weekend getaway is more likely to spark romance in their relationship than a gift. Of the 1,100 U.S. adults surveyed, 72% think traveling inspires romance.

More than three-quarters, or 77%, of those who travel as a couple say they have a good sex life, compared with 63% of couples who don't travel together. And 28% of the couples say their sex life actually improved after traveling together. Of those couples, 40% say the improvement was permanent.

"When you're away all of a sudden the e-mails don't happen, neighbors don't knock on the door, and the dog doesn't have to be walked, and you get to spend more time together," says Roger Dow, president of the U.S. Travel Association.

Even some frequent business travelers who take their spouses on work trips say it has a positive impact on their relationships.

"People don't realize that being a frequent flier (and) road warrior is a very lonely life," says Tamara Hall, a consultant in Bozeman, Mont. "When we travel together, it cuts the work and stress in half."

The survey, conducted from Nov. 26 to Dec. 9, also indicates that traveling together promotes longevity in the relationship.

Of those couples who travel together, 84% made it past the five-year mark in their relationship. Of those who don't, 76% had made it past five years.

Sarah Rodgers, senior research analyst at Edge Research, which conducted the survey, says couples who traveled together alone, rather than with friends or other couples, are more likely to feel closer and communicate better after a trip. Traveling allowed them to "talk and reconnect and also to share new experiences," she says.

But not all couples travel well together, says Joshua Klapow, a clinical psychologist at the University of Alabama at Birmingham.

"Just traveling together in and of itself is not going to make you a better couple, but learning how to travel together successfully is," he says. "Traveling together puts a couple in an extended period of being together more than their average interactions. That extended period can either enhance a relationship, or it can blow up in their faces."

For Allen Crockett, a frequent business traveler from Clayton, N.C., a recent weekend trip to Philadelphia with his wife kept them from breaking up.

"It reminded us of the reasons we fell in love, got married and decided to have a family," he says. "I moved back in, and we're celebrating our 18th anniversary in a few weeks."